Oh, yes. I used to use this stuff called Mare-Aleve from Foxden Equine and it really really works. Its all natural ingredients like raspberry leaves, chasteberry, & magnesium. Its now called Stability EQ: Foxden Equine Nutrition & Therapy - Products
I have two hot mares and it allows them to have enough energy for their performance demands, but it takes away the edge and quiets their minds.
Another product by them is called Quiessence, which I have never used but have heard good things.
I am feeding one of my mares this stuff: Equilibrium EQ? 60 Bar unit
And she hasnt been on them long enough for me to know if it's helping.
If not, I'll switch back to the Stability EQ.
Oh, one more thing, my boss has a gelding that is sure he's still a stallion. He has been on the Stability EQ for a long time and it very much has helped him.